Intel Alder Lake i5-12500T/Intel UHD -- Cannot Successfully Pass iGPU to VM with Q35 Machine Type

[SInisterPisces]

Hello,

This appears to be essentially the same bug as reported here in 2019 (never assigned): https://bugzilla.proxmox.com/show_bug.cgi?id=2381
It was also discussed here: https://forum.proxmox.com/threads/i...5-conflict-detected-with-stolen-region.57584/

I've got iGPU passthrough working using the latest PVE 8 tutorials, but it won't boot with the q35 machine type, so I can't use PCIe. Since I'm trying to pass through an iGPU, I need PCIe speeds.

I've included my VM config and the lspci output from inside the VM.

Please let me know what additional information would be useful for troubleshooting. This is what I have so far.

I'd really appreciate some help with this. This VM is so close to being usable.

 

[SInisterPisces]

Followup:

The solution to this was to disable ACPI within the VM options, as per this thread: https://forum.proxmox.com/threads/igpu-passthorugh-pci_hp_register-failed-with-error-16.132429/ (Thanks, @kjkent !).

Note: Make sure you have qemu-guest-tools installed inside the VM and enabled in the VM options. Otherwise the buttons in the Proxmox GUI won't be able to shutdown/restart the VM.
As it is, after shutting down the OS, you might get a black screen because the VM itself is still running. You'll need to manually STOP the VM at that point.

This is still broken for me.
This is what the PCI situation looks like inside my VM now. The Intel iGPU, in IOMMU group 0, appears to be trying to pull in the Intel Audio Device, in IOMMU group 9 ... along with all the other listed piece of real hardware in IOMMU group 9, which includes a lot of the guts of the real machine.

I'm surprised launching the VM doesn't crash the host.

I'm going to have to experiment with the IOMMU grouping fix on the wiki and hope it isolates the sound device from ... everything else in IOMMU group 9.